IL-22 and ACPA Levels and their Relationship to the Disease Activity in Rheumatoid Arthritis Patients

Aim: to determine ACPA IgG and IL-22 levels in RA patients and their relationship to the disease activity Place and duration of the study: A cross sectional study and prospective cohort study was performed from August 2020 to January 2021 in rheumatology outpatient clinic and laboratory of Al- Quwayiyah General hospital. Methodology: Forty five rheumatoid arthritis patients were included and 35 healthy participants free of any diseases considered as control group. The patients in this study met the American College of Rheumatology's 2010 guidelines. RA Disease activity was assessed for rheumatoid patients using DAS28 scoring. Serum samples collected from the patients and control to perform ESR, Hs-CRP, RF factors and also IL22 and ACPA IgG which were detected using sandwich ELISA and indirect solid phase enzyme immunoassay techniques respectively. Results: Out of the 45 RA patients, 34(75.6%) were females and 11(24.4%) were males aged from (28-67years) with median patient age 42 years. There was no statistically significant difference regarding age and sex between RA patients and control. Thirty (66.7%) of the 45 RA patients had low disease activity or remission, while 15 (33.3%) had moderate to extreme disease activity. Thirty two 32(71.1%) patients of the 45 RA patients had erosive disease. The level of ESR, hs-CRP and RF are increased in the patient group than control, in spite that there were significant differences in the Mean± SD among RA group and control group regarding RF, there was no significant statistical differences ESR, hs-CRP. in the study there was an increase in ACPA and IL-22 levels in patients suffering of RA; 21.52±1.29 U/ml and 71.22±10.63 pg\ml. respectively. While among control there was low serum levels; 14.06±2.01U/ml 33.25±2.41pg\ml and respectively. Significant statistical difference was observed regarding IL-22 and ACPA IgG levels among RA patients and control (P=0.038 and P=0.019 respectively). There is a significant positive relationship (positive correlation) detected between ACPA and IL-22 levels, (r=-0.810; p=0.597). The levels of IL-22 and ACPA were significantly associated with DAS 28. Their relationship was strong as the r value was 0.427 and 0.411 respectively. Conclusion: IL-22 and ACPA IgG levels were highly increased among RA patients in comparison to the control group. The IL-22 and ACPA IgG levels were strongly correlated with the rheumatoid disease activity, DAS 28. These results suggest that Il-22 can be used in association with ACPA IgG level as diagnostic and prognostic markers of rheumatoid arthritis